FR8252 Furuno radar & PSU 8 issue

My FR8252 25kw radar will now only work at short ranges of 1/2 mi or less. I believe it has something to do with the PSU 8 power unit. Any input on what this might be? Is their a fuse in the PSU8 that could cause this issue.
Thanks

If the fuse was blown, the PSU008 wouldn't work and you would have nothing. Was this system working fine and then this happened or is this just been moved/installed? What is the history.